1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.tv.tuner.hdhomerun; 18 19 import android.support.annotation.NonNull; 20 import android.util.Log; 21 import android.util.Pair; 22 23 import com.android.tv.tuner.hdhomerun.HdHomeRunDiscover.HdHomeRunDiscoverDevice; 24 25 import java.net.InetAddress; 26 import java.net.UnknownHostException; 27 import java.nio.BufferUnderflowException; 28 import java.nio.ByteBuffer; 29 import java.nio.ByteOrder; 30 import java.util.Arrays; 31 import java.util.Collections; 32 import java.util.List; 33 import java.util.zip.CRC32; 34 35 class HdHomeRunUtils { 36 private static final String TAG = "HdHomeRunUtils"; 37 private static final boolean DEBUG = false; 38 39 static final int HDHOMERUN_DEVICE_TYPE_WILDCARD = 0xFFFFFFFF; 40 static final int HDHOMERUN_DEVICE_TYPE_TUNER = 0x00000001; 41 static final int HDHOMERUN_DEVICE_ID_WILDCARD = 0xFFFFFFFF; 42 43 static final int HDHOMERUN_DISCOVER_UDP_PORT = 65001; 44 static final int HDHOMERUN_CONTROL_TCP_PORT = 65001; 45 46 static final short HDHOMERUN_TYPE_INVALID = -1; 47 static final short HDHOMERUN_TYPE_DISCOVER_REQUEST = 0x0002; 48 static final short HDHOMERUN_TYPE_DISCOVER_REPLY = 0x0003; 49 static final short HDHOMERUN_TYPE_GETSET_REQUEST = 0x0004; 50 static final short HDHOMERUN_TYPE_GETSET_REPLY = 0x0005; 51 52 static final byte HDHOMERUN_TAG_DEVICE_TYPE = 0x01; 53 static final byte HDHOMERUN_TAG_DEVICE_ID = 0x02; 54 static final byte HDHOMERUN_TAG_GETSET_NAME = 0x03; 55 static final int HDHOMERUN_TAG_GETSET_VALUE = 0x04; 56 static final int HDHOMERUN_TAG_ERROR_MESSAGE = 0x05; 57 static final int HDHOMERUN_TAG_TUNER_COUNT = 0x10; 58 static final int HDHOMERUN_TAG_BASE_URL = 0x2A; 59 60 static final int HDHOMERUN_CONTROL_CONNECT_TIMEOUT_MS = 2500; 61 static final int HDHOMERUN_CONTROL_SEND_TIMEOUT_MS = 2500; 62 static final int HDHOMERUN_CONTROL_RECEIVE_TIMEOUT_MS = 2500; 63 64 /** 65 * Finds HDHomeRun devices with given IP, type, and ID. 66 * 67 * @param targetIp {@code 0} to find target devices with broadcasting. 68 * @param deviceType The type of target devices. 69 * @param deviceId The ID of target devices. 70 * @param maxCount Maximum number of devices should be returned. 71 */ 72 @NonNull findHdHomeRunDevices( int targetIp, int deviceType, int deviceId, int maxCount)73 static List<HdHomeRunDiscoverDevice> findHdHomeRunDevices( 74 int targetIp, int deviceType, int deviceId, int maxCount) { 75 if (isIpMulticast(targetIp)) { 76 if (DEBUG) Log.d(TAG, "Target IP cannot be multicast IP."); 77 return Collections.emptyList(); 78 } 79 try { 80 HdHomeRunDiscover ds = HdHomeRunDiscover.create(); 81 if (ds == null) { 82 if (DEBUG) Log.d(TAG, "Cannot create discover object."); 83 return Collections.emptyList(); 84 } 85 List<HdHomeRunDiscoverDevice> result = 86 ds.findDevices(targetIp, deviceType, deviceId, maxCount); 87 ds.close(); 88 return result; 89 } catch (Exception e) { 90 Log.w(TAG, "Failed to find HdHomeRun Devices", e); 91 return Collections.emptyList(); 92 } 93 } 94 95 /** Returns {@code true} if the given IP is a multi-cast IP. */ isIpMulticast(long ip)96 static boolean isIpMulticast(long ip) { 97 return (ip >= 0xE0000000) && (ip < 0xF0000000); 98 } 99 100 /** Translates a {@code byte[]} address to its integer representation. */ addressToInt(byte[] address)101 static int addressToInt(byte[] address) { 102 return ByteBuffer.wrap(address).order(ByteOrder.LITTLE_ENDIAN).getInt(); 103 } 104 105 /** Translates an {@code int} address to a corresponding {@link InetAddress}. */ intToAddress(int address)106 static InetAddress intToAddress(int address) throws UnknownHostException { 107 return InetAddress.getByAddress( 108 ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(address).array()); 109 } 110 111 /** Gets {@link String} representation of an {@code int} address. */ getIpString(int ip)112 static String getIpString(int ip) { 113 return String.format( 114 "%d.%d.%d.%d", (ip & 0xff), (ip >> 8 & 0xff), (ip >> 16 & 0xff), (ip >> 24 & 0xff)); 115 } 116 117 /** 118 * Opens the packet returned from HDHomeRun devices to acquire the real content and verify it. 119 */ openFrame(byte[] data, int length)120 static Pair<Short, byte[]> openFrame(byte[] data, int length) { 121 if (length < 4) { 122 return null; 123 } 124 ByteBuffer buffer = ByteBuffer.wrap(data); 125 short resultType = buffer.getShort(); 126 int dataLength = buffer.getShort() & 0xffff; 127 128 if (dataLength + 8 > length) { 129 // Not finished yet. 130 return null; 131 } 132 byte[] result = new byte[dataLength]; 133 buffer.get(result); 134 byte[] calculatedCrc = getCrcFromBytes(Arrays.copyOfRange(data, 0, dataLength + 4)); 135 byte[] packetCrc = new byte[4]; 136 buffer.get(packetCrc); 137 138 if (!Arrays.equals(calculatedCrc, packetCrc)) { 139 return Pair.create(HDHOMERUN_TYPE_INVALID, null); 140 } 141 142 return Pair.create(resultType, result); 143 } 144 145 /** Seals the contents in a packet to send to HDHomeRun devices. */ sealFrame(byte[] data, short frameType)146 static byte[] sealFrame(byte[] data, short frameType) { 147 byte[] result = new byte[data.length + 8]; 148 ByteBuffer buffer = ByteBuffer.wrap(result); 149 buffer.putShort(frameType); 150 buffer.putShort((short) data.length); 151 buffer.put(data); 152 buffer.put(getCrcFromBytes(Arrays.copyOfRange(result, 0, data.length + 4))); 153 return result; 154 } 155 156 /** Reads a (tag, value) pair from packets returned from HDHomeRun devices. */ readTaggedValue(ByteBuffer buffer)157 static Pair<Byte, byte[]> readTaggedValue(ByteBuffer buffer) { 158 try { 159 Byte tag = buffer.get(); 160 byte[] value = readVarLength(buffer); 161 return Pair.create(tag, value); 162 } catch (BufferUnderflowException e) { 163 return null; 164 } 165 } 166 readVarLength(ByteBuffer buffer)167 private static byte[] readVarLength(ByteBuffer buffer) { 168 short length; 169 Byte lengthByte1 = buffer.get(); 170 if ((lengthByte1 & 0x80) != 0) { 171 length = buffer.get(); 172 length = (short) ((length << 7) + (lengthByte1 & 0x7F)); 173 } else { 174 length = lengthByte1; 175 } 176 byte[] result = new byte[length]; 177 buffer.get(result); 178 return result; 179 } 180 getCrcFromBytes(byte[] data)181 private static byte[] getCrcFromBytes(byte[] data) { 182 CRC32 crc32 = new CRC32(); 183 crc32.update(data); 184 long crc = crc32.getValue(); 185 byte[] result = new byte[4]; 186 for (int offset = 0; offset < 4; offset++) { 187 result[offset] = (byte) (crc & 0xFF); 188 crc >>= 8; 189 } 190 return result; 191 } 192 HdHomeRunUtils()193 private HdHomeRunUtils() {} 194 } 195